Mitral valve (MV) disease is common in humans and not infrequently fatal. Mitral regurgitation, in particular, demonstrates a strongly-graded relationship between severity and reduced survival. MV surgery, both repair and replacement, are commonly exercised treatment options for mitral regurgitation. Imaging and assessment of the mitral valve has traditionally been achieved by qualitative 2D ultrasound image analysis. Recently, real-time three-dimensional transesophageal echocardiography (rt-3DTEE) has become widely available and implemented. 3D image-based modeling of the mitral valve is increasingly useful, and finite element analysis (FEA) has been applied to the MV frequently over the last 20 years.
To date, the majority of valve morphometry studies have employed manual tracing to reconstruct valve geometry from 3D echocardiographic image data. Therefore, the first objective herein is to introduce an alternative semi-automated approach to valve morphometry based on a simple and rapid approach to user-initialized image segmentation that exploits the contrast between the mitral valve tissue and surrounding blood pool in rt-3DTEE images. The valve is subsequently modeled using 3D continuous medial representation to obtain localized thickness maps of the mitral leaflets.
The inventors recently provided a framework for the application of in vivo MV geometry and FEA to human MV physiology, pathophysiology, and repair. (see, Xu C, Brinster C J, Jassar A S, et al. A novel approach to in vivo mitral valve stress analysis. Am J Physiol Heart Circ Physiol. 299(6):1790-1794, 2010). Therefore, a second objective herein is to demonstrate that the semi-automated 3D MV model can be loaded with physiologic pressures using FEA, yielding reasonable and meaningful stress and strain magnitudes and distributions. Furthermore, the inventors endeavor to demonstrate this capability in both healthy and diseased human mitral valves. The methods of the invention address these and other objectives.